Benjamin Kuipers, Joseph Modayil, Patrick Beeson, Matt MacMahon, and
Francesco Savelli. 2004.
Local metrical and global topological maps
in the Hybrid Spatial Semantic Hierarchy.
IEEE International Conference on Robotics and Automation (ICRA-04).
Topological and metrical methods for representing spatial knowledge have
complementary strengths. We present a hybrid extension to the Spatial
Semantic Hierarchy that combines their strengths and avoids their
weaknesses. Metrical SLAM methods are used to build local maps of
small-scale space within the sensory horizon of the agent, while
topological methods are used to represent the structure of large-scale
space. We describe how a local perceptual map is analyzed to identify a
local topology description and is abstracted to a topological place. The
map-building method creates a set of topological map hypotheses that are
consistent with travel experience. The set of maps is guaranteed under
reasonable assumptions to include the correct map. We demonstrate the
method on a real environment with multiple nested large-scale loops.